Machine tool and more particularly to marking machine with a center



MACHINE TQOL AND MORE PARTICULARLY TO MARKING MACHINE WITH A CENTERFiled Aug. 2, 1946 March 15, 1949. PHILIPPE 2,464,415

Patented Mar. 15, 1949 MACHINE TOOL AND MORE PARTICULARLY T MARKINGMACHINE WITH A CENTER Maurice Philippe, Courbevoie, France, assignor toSociete Anonyme A.

G., and Societe Civile dEtude des Inventions et lrocedes Philippe,

laris, France Application August 2, 1946, Serial No. 687,920 In FranceOctober 18, 1943 Section 1, Public Law 690, August 8, 1946 Patentexpires October 18, 1963 6 Claims.

The present invention has for its main object to provide an improvementin machine-tools and in particular in marking machines with a center,which comprises a movable tool-holder on an extension arm supported inover-hanging position on the frame. The invention aims at overcoming thedrawbacks which arise from the elastic deformation tov which theextension arm is subject, however great the moment of inertia thereofmay be, under the eifect of the weight of the tool-holders; suchdeformations are, besides, variable according to the position of thetoolholders on the extension arm.

To this effect, this invention is chiefly characterised by the novelapplication to such machines of means for, at least in part,compensating the bending moment exerted on the extension arm by theWeight of the tool-holder so as to relieve saidextension arm of thesupporting function and make said arm serve solely the function ofgvuilding the horizontal movements of the tool.

The means considered to be preferable according to this inventionconsists in balancing the weight of the tool-holder, at least in part,by an opposing force exerting no reaction upon the extension arm.

This invention comprises Within its scope all forms of embodiment ofthat principle, and in particular those which are characterised by thefollowing features applied severally or in all their combinations (a)The reaction of the opposing force is exerted upon a support independentof the extension arm.

(b) The opposing force is provided by a counter-weight.

(c) The tool-holder and the counter-weight are interconnected by aflexible connecting means guided by pulleys or equivalent means such assprockets and chain, or the like.

((1) The pulleys are supported by a carriage movable on the independentsupport.

(e) The displacements of the movable carriage are controlled by those ofthe tool-holder along the extension arm.

(is) The counter-weight balancing the toolholder is vertically guided byan element rigid with the movable carriage.

(g) The independent support comprises a guide-way vfor guiding themovable carriage par- I allel to the extension arm.

(i) The independent support is pivoted on the frame substantially at itscenter and its rear end rests upon an adjustable abutment.

(9') An opposing force such as that exerted by a counter-weight or aspring retains the independent support upon the adjustable rear abutmentthereof. I

(k) Abutments on the independent support restrict the movements of themovable carriage.

(Z) The resulting force of the various fixed and movable loads exertedupon the frame remains at all times within the polygon of support of thelatter, Whatever the position of the movable elements may be.

This invention is applicable to all machinetools comprising atool-holder movable upon an over-hanging extension arm. However, it ismore particularly adapted to precision machines such as large capacitymarking machines with a center. This invention then enables theproviding of a new article of manufacture constituted by a markingmachine with a center of large capacity, which is entirely clear of anyupstanding standard on three of its sides, whereas known machinescomprise a pair of standards between which .is mounted the support forthe tool; it will be understood that this invention, the use of whicheliminates any elastic deformation in the extension arm during thehorizontal displacements of the tool-holder, and maintains for allpositions of the latter a constant distance between the tool and thework-table of the machine, permits the manufacturer to do away with suchstandards. The limitation incurred by the latter with respect to thedimensions of work-pieces which the machine is capable to machine, istherefore suppressed, while the ease of access for the operator isenhanced. Such outstanding advantages are characteristic of the newarticle of manufacture constituted by the marking machine with a centeraccording to this invention.

The appending drawing represents by way of example only, and indiagrammatic showing, a form of embodiment of such a marking machinewith a center.

The frame I is rested upon a base '2 and comprises at its upper portionan extension arm 3 having a pair of slide-ways 4 and 5 on which isreciprocable a slide-block 6 receiving the toolholder 7. A horizontalgirder '8 surmounts the frame I and the arm 3 said girder is pivoted atits center on a support 9 secured to the 1 frame by means of ahorizontal pin in; the end thereof opposite to the extension arm restsupon an adjustable abutment formed by a supporting screw H, making itpossible to adjust the horizontality of said girder, which has no pointof contact with the extension arm on which the tool-holder slide-block 6is horizontally movable. A carriage I2 is displaceable through themedium of rollers 13 and I4 on the upper side of the girder 8 which thusconstitutes a support and a runway for said carriage l2; the lattercarries a pair of pulleys l5 and it over which is trained a cable I!fixed on one hand to the tool-holding head 1 and on the other hand to abalancing counter-weight l8 displaceable within the frame I. Formaintaining at all times the end of the supporting girder 8 inengagement with the supporting screw H, a fixed counter-weight l9produces on the pivotal axis l0 an opposing moment which at all times isgreater than that set up by the tool-holder, even when the latteroccupies its farthest position at the very end of the arm 3. Theslide-block 6 is made to drive the carriage 12 by any suitable means,such asa projection engaging a yoke 2i rigid with the carriage 1.Projection 20 is preferably formed as a bushing freely rotatable on apin rigid with 3 the carriage l2. Said yoke is so designed as to permitof a slight amount of relative vertical displacement in translationbetween said bushing and the arms of said yoke.

Thanks to the above arrangement, the girder 8 supports the tool-holdinghead 7 and the balancing counter-weight I8 thereof, without the arm 3taking any part in said supporting action; the possible deformationswhich the girder 8 may be subject to under such load will be merelyexpressed as a vertical displacement of the counter-weight l8, with-outany additional stress being applied to the arm, the function of which issolely to guide the tool-holding slideblock 6 in the horizontal movementthereof. The vertical displacement of the tool-holding head 1 isaccomplished without any effort thanks to the balancing counter-weightl8. A guiding device 24 integral with the carriage i2 prevents anyoscillations which could arise from the effect of inertia during thereciprocation of said carriage.

The whole structure is so dimensioned and disposed that the resultant(RA for the foremost position A of the toolholder, RB for the rearmostposition B of the tool-holder) of the various movable loads (slide-block6, tool-holder 1, carriage l2, counter-weight I8) and the fixed loads(supporting girder 8 and counter-weight l9) applied to the frame I atall times remains within .the supporting polygon of the frame, even forthe maximum displacements. In this way, the frame is made to work'incompression only; all bending stresses are eliminated, and thereby therelatively considerable deformations which could result therefrom.

By the use of the arrangements according to this invention, there isprovided a marking machine with a center making possible the machiningof parts of large dimensions, while at the same time permitting of easyaccess for the operator. In fact, the work-table is entirely clear ofany upstandin support on three of its sides, whereas according to theconventional arrangement, large capacity marking machines with a centercomprise a pair of standards between whichthe toolholder is mounted. Thespacing between such standards defines a maximum dimension for thework-pieces which it is possible to machine on such machines. Accordingto this invention, on.

the contrary, although the supporting arm is over-hanging with respectto the frame and thereby enables the above mentioned results to beattained, any elastic deformation of the supporting arm, when thetool-holding slide-block is subject to longitudinal reciprocation, issuppressed and the spacing between the tool and the work-table ismaintained accurately constant for all positions which the tool mayoccupy along said arm.

Of course, the form of embodiment and application which has beendescribed and illustrated has been given by way of example only, and itis possible, without exceeding the scope of this invention, to alter inany suitable way the number, shape, type, disposition and mounting ofthe various elements.

In particular, the reaction element for compensating the weight of thetool-holder could be other than a counter-weight; it could for instancebe a support independent of the frame of the machine acting in themanner of a crane and arranged for example within said frame. Therecould likewise be conceived an adjustable tension spring devicefulfilling a function similar to that of the above-describedcounter-weight, or any other device capable of assuming the samecompensating function. Pulleys I5 and 16 with their cable ll could bereplaced by any equivalent device, such as chain and sprockets or thelike.

What I claim as my invention and desire to secure by Letters Patent is:

1. In a marking machine, a frame, an extension arm integral with saidframe in overhangin position, a tool-holder, guiding means for guidingsaid tool-holder horizontally and vertically on saidextension arm,compensating means for at least partially compensating the load of saidtoolholder and said guiding means on said extension arm, a supportindependent of said extension arm and carried by said frame, and meansconnected with said tool-holder and With said compensating means fortransferring to said support the stresses due to said load and to saidcompensating means.

2. In a marking machine, a frame, an extension arm integral with saidframe in overhanging po sition, a tool-holder, guiding means for guidingsaid tool-holder horizontally and vertically on said extension arm,compensating means for at least partially compensating the load of saidtoolholder and said guiding means on said extension arm, a supportindependent of said extension arm, a horizontal pivotable axis carriedby said frame and by said independent support, adjusting means foradjusting the position of said independent support and thereby theparallelism of said support with said horizontal guiding means and meansconnected with said tool-holder for transferring to said support thestresses due to said load and to said compensating means.

3. In a markin machine, a frame, a horizontal extension arm integralwith said frame in over-hangin position, a tool-holder, guiding meansfor guiding said tool-holder horizontally and vertically on saidextension arm, a support independent of said extension arm, a horizontalpivotable axis carried by said frame and said independent support,adjusting means for adjusting the parallelism of said independentsupport with said horizontal guiding means, means for compensating theload of said tool-holder and of the horizontally and vertically guidingmeans there-- of, and a carriage connected with said tool-holder andmovable in translation on said independent support for supporting thestresses due to said load and to said compensating means.

4. In a marking machine, a frame, a horizontal extension arm integralwith said frame in overhanging position, a tool-holder, guiding meansfor horizontally and vertically guiding said toolholder on saidextension arm, a support independent of said extension arm, a horizontalpivotable axis carried by said frame and said independent support,adjusting means for adjusting the parallelism of said independentsupport with said horizontal guiding means, a carriage movable intranslation on said independent support, friction rollers interposedbetween said carriage and said independent support, pulleys carried bysaid carriage, and a flexible cable trained over said pulleys andbearing at one of its ends said tool-holder and at its other end acompensating counterweight.

5. In a marking machine, a frame, a horizontal extension arm integralwith said frame in overhanging position, a tool-holder, a slide-block,horizontal slide-ways provided in said extension arm for thedisplacement of said slide-block, vertical slide-ways provided in saidslide-block for the displacement of said tool-holder, a supportindependent of said extension arm, a horizontal pivotable axis carriedby said frame and said independent support, adjusting means foradjusting the parallelism of said independent support with saidhorizontal slideways, a carriage movable in translation on saidindependent support, friction rollers interposed between said carriageand said independent support, pulleys carried by said carriage, aflexible cable trained over said pulleys and bearing at one of its endssaid tool-holder and at its other end a compensating counter-weight, avertical slideway integral with said carriage for guiding saidcounter-weight, a projection integral with said carriage and a yokeintegral with said slide-block adapted to engage said extension.

6. In a machine-tool for precise machining in which the Weight of thetool-holder should not exert on the support means thereof any bendingstress detrimental to the precision of adjustment, a frame, a horizontalextension arm integral with said frame in over-hanging position, atool-holder, a slide-block, horizontal slide-ways provided in saidextension arm for the displacement of said slide-block, verticalslide-ways provided in said slide-block for the displacement of saidtool-holder, a support independent of said extension arm, a horizontalpivotable axis carried by said frame and said independent support,adjusting means for adjusting the parallelism of said independentsupport with said horizontal slide-ways, a carriage movable intranslation on said independent support, friction rollers interposedbetween said carriage and said independent support, pulleys carried bysaid carriage, a flexible cable trained over said pulleys and bearing atone of its ends said tool-holder and at its other end a compensatingcounter-weight, a vertical slide-way integral with said carriage forguiding said counterweight, a projection integral with said carriage anda yoke integral with said slide-block adapted to engage said extension.

MAURICE PHILIPPE.

5 file of this patent:

FOREIGN PATENTS Country Date Great Britain Aug. 17, 1933 Number

